The present invention relates to a pressure compensating liquid flow regulator, and more particularly to such a regulator which is of reduced length.
The prior art teaches a liquid flow regulator which controls hydraulic flow to a predetermined level, regardless of the differential pressure across the regulator. For example, such a flow regulator is available under the tradename 500 Flosert from the Lee Company of Westbrook, Conn. The product maintains hydraulic flow at a predetermined level, regardless of the differential pressure across the regulator, by maintaining a constant pressure drop across a fixed or sensing orifice. The spring or biasing means of the flow regulator is disposed outside of the metering poppet, thus limiting the utility of the regulator in situations affording only a limited axial length for the regulator. For example, a slot for a flow regulator may have an installation bore length of less than 1 inch, while an installation bore length in excess of 2 inches is required for the prior art regulator. Accordingly, it would be desirable to have a flow regulator having an installation bore length of less than 1 inch (about half of the installation bore length of the prior art regulator), and preferably no more than 0.9 inch.
The prior art flow regulator did not prove to be entirely satisfactory in use because it could not regulate the liquid flow to a sufficiently tight range to be useful for particularly demanding customer applications. Thus whereas the prior art device regulated flow to about .+-.10%, critical applications require regulation of the flow to about .+-.3% (less than a third of the variation of the prior art regulator), and preferably no more than .+-.0.7%.
Accordingly, it is an object of the present invention to provide a educed length, pressure compensating liquid flow regulator.
Another object is to provide such a regulator having an installation bore length of less than 1 inch, and preferably no more than 0.9 inch.
A further object is to provide such a regulator which can regulate flow to about .+-.3%, and preferably no more than .+-.0.7%.
It is also an object of the present invention to provide such a flow regulator which is simple and economical to manufacture, maintain and use.